This paper is the 28th consecutive installment of the annual review of research concerning
the endogenous opioid system, now spanning over a quarter-century of research. It …

Since the first description of their opioid properties three decades ago, dynorphins have
increasingly been thought to play a regulatory role in numerous functional pathways of the …

Visceral pain is experienced by 40% of the population, and 28% of cancer patients suffer
from pain arising from intra‐abdominal metastasis or from treatment. Neuroanatomy of …

Background Peripherally selective opioids may be beneficial in visceral pain management
due to absence of centrally mediated side effects. The objectives of this study were:(1) to …

Oxycodone, a semisynthetic opioid analgesic, is widely used in clinical practice. Oxycodone
was first synthesized from thebaine in Germany in 1917. 1 For decades, researchers have …

IBS is a common disorder that affects approximately 5–20% of the populations of Western
countries; the main symptoms are abdominal pain and erratic, altered bowel habits, often …

Immediately following spinal cord injury (SCI) patients experience pain associated with
injury to the spinal cord and nerves as well as with accompanying peripheral injuries. This …

The three opioid receptors, mu, delta and kappa all mediate analgesia, and knockout mice
with opioid receptor deletion have proven unique tools to investigate in vivo opioid …

Opioids are one of the most prescribed drug classes for treating acute pain. However,
chronic use is often associated with tolerance as well as debilitating side effects, including …

κ opioid receptor (κOR) is a subtype of opioid receptors, and there are two major κOR
agonists currently available, morphinans and arylacetamides, which are structurally distinct …